Pumps generally require shaft packing or mechanical seals to ensure the fluid to be pumped does not harm or cause catastrophic damage to the pump motor, or to ensure the fluid does not leak therefrom. In some cases, a liquid seal can be used instead of shaft packing or mechanical seals, which is much more economical and requires little to no maintenance. U.S. Pat. No. 4,772,183 to Durden, which is incorporated herein by reference, described using a liquid seal that relies on a vacuum in the extension or support tube to keep tube clear of oil or fluid and prevent flooding of motor or motor bearings. It has now been discovered that a potential disadvantage of such a pump is that the vacuum may be lost due to vapor from the liquids forming in the extension tube. In such an event, vapor may open the relief valve at the top of the extension tube allowing flooding of the tube and motor bearings.
Accordingly, it can be seen that needs exist for an improved pump. It is to the provision of a liquid sealed pump with dynamic turbo tech impeller meeting these and other needs that the present invention is primarily directed.